N-substituted derivatives of benzoxazolones and sulfur-containing analogues thereof are known. However, it is believed that no N-glycidyl derivatives of these benzoheterocycles have been made or proposed. The N-methyl derivative of 2-(3H)-benzothiazolone has been converted to the hydrazone, which has utility as a colorimetric analytical reagent. 2-(3H)-benzothiazolthione, as such, has utility as a vulcanization accelerator. Otherwise, as far as is known to the present inventor, nothing relevant to the possible utility of the N-glycidyl derivatives has been disclosed in the literature.